Endobronchial Ultrasound in Suspected Non-Malignant Mediastinal Lymphadenopathy

Endobronchial ultrasound (EBUS) bronchoscopy with transbronchial needle aspiration (TBNA) is a well-established tool in mediastinal staging in lung cancer and gains importance in exploration of non-malignant lymphadenopathy. The aim of this study was to evaluate the role of EBUS-TBNA in suspected non-malignant diseases.

A retrospective, single-center, observation analysis of endobronchial ultrasound bronchoscopy procedures was performed in a university medical center between March 2013 and July 2015. All patients with suspected non-malignant mediastinal lymphadenopathy were included. Cytopathological and microbiological results of EBUS were compared to clinical diagnosis 6 months after procedure and performance of EBUS was contrasted to malignant indications.

During study period, 333 EBUS bronchoscopies in 315 patients with mediastinal lymphadenopathy were performed. 111 out of 315 (35 %) patients had neither primary signs nor history of a malignant disease, categorised as patients with suspected non-malignant disease. 245 lymph nodes were sampled (median size 15 mm [IQR10 - 19]). Preferred station for TBNA was lymph node station 7 (38 %). Cytopathological findings revealed non-specific inflammation (n = 81; 70 %), carcinoma (n = 7; 6 %), epithelioid cell granulomas (n = 20; 17 %). 7 samples (6 %) were non-representative. Microbiologic testing of lymph nodes identified 3 infections (Mycobacteria tuberculosis [n = 2] and Nocardia nova [n = 1]) relevant to antibiotic therapy. Minor adverse events were observed in 9 out of 115 (8 %) patients. Sensitivity of EBUS-TBNA intervention in suspected non-malignant disease was 76 % and specificity 96 %.

EBUS-TBNA revealed a specific cause for suspected non-malignant lymphadenopathy in one-third of cases and was associated with excellent specificity. Predominant specific causes were granuloma, besides from tumor. In 3 patients pathogen could be isolated by TBNA.